To meet growing traffic requirements and services of various requirements, the 3rd Generation Partnership Project (3GPP) standardization organization is currently developing standards for a next-generation mobile communications system. Inactive state is a newly introduced radio resource control (RRC) state, which is referred to as “RRC inactive state” or “inactive state” below. As in an idle state, in the inactive state, an RRC connection between a terminal and a network is disconnected, and the terminal does not need to receive downlink data, so as to achieve the same power-saving effect as in the idle state. Unlike in the idle state, in the inactive state, when a terminal needs to enter a connected state, for example, the terminal has uplink data that needs to be sent, or a network pages the terminal to enter the connected state, the terminal can restore the connected state based on a saved context of the terminal. On a network side, an access network device requested by the terminal requests a context of the terminal from an original serving access network device of the terminal, so that the access network device can also obtain the context of the terminal, and restore a connection to the terminal based on the context.
The next-generation mobile communications system has a higher delay requirement, and how to reduce time for a terminal to restore from an RRC inactive state to an RRC connected state becomes a technical problem that needs to be urgently resolved.